Back in 2007, Toyota trumpeted its bulked-up Tundra as a game-changer that would cut into Detroit's dominance of the U.S. pickup truck market.

DETROIT — Back in 2007, Toyota trumpeted its bulked-up Tundra as a game-changer that would cut into Detroit's dominance of the U.S. pickup truck market.

"The truck that's changing it all" was the tagline from an ad that featured the beefy Tundra pulling a 10,000-pound trailer up a steep ramp.

But after six years on the market, the Tundra hasn't changed much of anything. Instead, Toyota learned that unlike car buyers, American pickup owners are still fiercely loyal to their Fords, Rams and Chevrolets. And that Detroit feverishly guards its lead in the high-margin truck business.

Toyota rolled out the 2014 Tundra on Thursday at the Chicago Auto Show, minus lofty sales goals or talk of breaking into Detroit's cash box. The new version goes on sale in September. The price and gas mileage haven't been announced.

Alec Gutierrez, senior market analyst for Kelly Blue Book, says Tundra won't lure new buyers unless it costs less or offers compelling features to make it different.

Longtime Detroit buyers agree. Jon Carey, who co-owns a drywall business near Ann Arbor, Mich., hauls tools and building materials with two Ram pickups purchased in 2006, and he sees no reason to switch.

"If you're just talking apples-to-apples, in my opinion, they'll never break into it," Carey said of Toyota. "If they were giving the same price point, I don't know that I would necessarily switch. There would have to be some real reason behind it."

The 2014 Tundra has a tougher squared-off look with a bold grille and more aerodynamic exterior, a more comfortable interior and a long list of practical and luxury features, such as a blind spot monitor and a standard backup camera.

But it lacks the type of changes Gutierrez hinted at. For instance, the choice of engines remains the same. General Motors, meanwhile, is offering more powerful and efficient motors with its new Chevy and GMC full-size pickups, which go on sale in the spring. And at last month's Detroit auto show, Ford gave a sneak peak of a new F-Series truck — due out next year — which it says will weigh far less to improve fuel economy.

Instead, the world's leader in auto sales seems happy to protect the Tundra's 6 percent share of the big pickup market — especially when truck sales are rising as the economy recovers from the Great Recession. Gas mileage will be about the same as the current Tundra, 18 to 20 miles per gallon on the highway. Toyota says.

Truck-buyer loyalty gives companies like Ford — which started building pickups in 1925, 40 years before Toyota sold its first pickup in America — a real advantage. Last year, 36 percent of F-150 buyers traded in an F-150, according to Edmunds.com. That's better than the loyalty rate for Toyota's best-selling Camry sedan. Only about 28 percent of Tundra buyers traded in a Tundra last year.

When Toyota's first big pickup came out in the early 1990s, it didn't measure up to the F-Series, Chevrolet Silverado or Chrysler's Ram. It was smaller and lacked the powerful engines needed to tow heavy loads. Sales in 2006 — a huge year for trucks — were just under 125,000, only a fraction of the nearly 800,000 F-Series trucks sold by Ford.

But Toyota had its sights set on Detroit. It built the Tundra at a factory in Texas, the heart of truck country. The new Tundra had a brawnier look, a larger bed and a 5.7-liter, 381-horsepower V-8. It was 700 pounds heavier, and its towing capacity increased by 3,000 pounds. Toyota brazenly predicted sales of 200,000 a year. In 2007 it came close, selling almost 197,000.

Detroit soon updated its pickups with powerful and more efficient engines, new transmissions and innovative features. Then the financial crisis and recession hit and truck sales fell at all automakers. Tundra sales hit a low of 79,000 in 2009. About 102,000 Tundras were sold last year, still less than one-sixth of Ford's 645,000.